According to the Centers for Disease Control and Prevention (CDC), around 30.8 million adults in the United States (US) currently smoke cigarettes. That's a lot of people who smoke. We know smoking is damaging for most of the body systems, but what about fertility? Let's take a look at the impact of smoking on male fertility and what you can do if you’re a smoker who’s trying to conceive.
- Robust research indicates a strong link between smoking and reduced male fertility.
- Smoking may impact sperm count, motility, morphology, genetic health, and more.
- If you’re trying to conceive, quitting is your best option. Your sperm health can recover within 6 months of quitting.
The research behind smoking and fertility
The American Society for Reproductive Medicine (ASRM) advises that 21% of women of reproductive age and 22% of men of reproductive age in the US smoke cigarettes. They also estimate that smokers are about twice as likely to experience infertility, compared to non-smokers.
A large 2011 meta-analysis — including 57 observational studies and over 29,000 men — found cigarette smoking had adverse effects on all sperm parameters, including semen volume, sperm density, total sperm counts, and percentage of sperm with progressive motility.
The correlation between smoking and male infertility/decreased fertility is quite consistent across most clinical studies, and there is fairly robust research on the topic of smoking on sperm health. Here’s a review of some of the research on how smoking affects your sperm.
How smoking affects sperm count
Sperm concentration refers to how densely packed sperm are within the semen, AKA how many sperm you have (sperm count). Normal sperm concentration is 15 million sperm per milliliter of semen; however, above 40 million sperm per milliliter is ideal for conception. Anything below 15 million sperm per milliliter is considered low.
A 2019 study examining 1,631 healthy fertile men in China found that smoking, especially smoking more than 20 cigarettes per day, was associated with decreased sperm count. Earlier studies concur, with one review identifying up to a 24% lower sperm concentration in smokers compared to non-smokers.
This is important to consider because a low sperm count can make it more difficult to conceive naturally.
How smoking affects sperm motility
Sperm motility refers to how efficiently your sperm moves. Semen analysis looks at both:
- total motility: what percentage of sperm are moving at all
- progressive motility: what percentage of sperm are moving efficiently, in large circles or forward motion
A 2003 study investigated the semen quality of males in couples experiencing infertility. It found that smoking was associated with a 16.6% decrease in total motile sperm. In a more recent analysis, sperm motility decreased by 5.25% among smokers compared to non-smokers. Another retrospective study including 715 men identified a significant effect of smoking more than ten cigarettes per day in patients with varicocele on sperm motility.
If you have poor sperm motility parameters, the sperm do not move properly, making it more difficult to reach and fertilize the egg. This can lead to male infertility.
How smoking affects sperm morphology
Morphology is the shape, size, and structure of your sperm. Why is sperm morphology important? Well, if a sperm has defects, it can have difficulty swimming to and fertilizing an egg. During a semen analysis, the morphology parameter measures what percentage of your sperm have a normal form.
In 2006, a small study published in the British Medical Journal found that smoking decreased sperm quality. Smokers had significantly lower normal sperm morphology than non-smokers — and smokers were more than twice as likely to be diagnosed with teratozoospermia, or poor sperm morphology.
The aforementioned study looking at varicocele patients also found a strong correlation between smoking and low sperm morphology. Other studies have also concluded that smoking is associated with a significant decrease in sperm morphology.
How smoking affects sperm DNA fragmentation
If sperm DNA is damaged or broken, known as DNA fragmentation, it can lead to problems with fertilization, embryo development and implantation, and increased miscarriage rates. It can make conception and live birth less likely.
Environmental and lifestyle factors have been identified as possible causes of DNA fragmentation in sperm, such as air pollution, poor diet, smoking, and drinking. Studies show the sperm of smokers has increased DNA fragmentation. They have also noted that paternal smoking is associated with an increased incidence of birth defects and disease in the child. Further studies are needed to really understand how DNA fragmentation affects the baby.
How smoking affects testosterone and hormone health
The effect of smoking on sperm health is clear. But the relationship between tobacco and hormones is less understood.
Studies are contradictory, with some showing no effect from smoking on androgens and others finding smoking is associated with an increase in testosterone. Meanwhile, a 2015 study found smoking reduced reproductive hormone levels — including all three of the primary male fertility hormones: follicle-stimulating hormone, luteinizing hormone, and testosterone.
More research and extensive studies are needed to develop a deeper understanding of smoking on male reproductive hormones.
Smoking and trying to conceive
Although we've looked at the direct impact of smoking on sperm, there are other factors to consider when trying to conceive.
Firstly, smoking is strongly associated with erectile dysfunction. In fact, some studies have shown that men who smoke are three times more likely to experience erectile dysfunction. It is also associated with low libido. Although not direct causes of infertility, these issues can make trying to conceive more difficult.
Some research also shows that, if a man smokes, it can also negatively affect his female partner — and women exposed to secondhand smoke can have decreased fertility. One study found that secondhand smoke significantly reduced the number of eggs retrieved during IVF. So, it's possible that smoking might not just affect your fertility but that of your partner too.
If you are embarking on assisted reproduction such as IVF or ICSI, then studies suggest that if the male partner smokes, it can contribute to decreased IVF success rates. It appears paternal smoking is equally impactful on assisted reproduction success rates as maternal smoking.
Bottom line: if you’re a smoker who’s trying to get your partner pregnant, it’s time to quit smoking — or at least drastically reduce the number of cigarettes you smoke.
What about other forms of tobacco and nicotine?
How do cigars affect male fertility?
Cigars are no healthier than cigarettes when it comes to smoking, smoking-related diseases, and the impact of smoking on fertility. Actually, one large cigar can contain as much nicotine as a whole pack of cigarettes. Cigars also don't just contain tobacco; they are wrapped in a material or leaf containing tobacco.
How does vaping or using e-cigarettes affect male fertility?
Vaping or e-cigarettes have increased in popularity over the years to assist people with quitting smoking. As you don't burn tobacco when vaping, it doesn't produce as many harmful toxins, therefore is considered “safer” than smoking traditional cigarettes.
But even nicotine-free vapes can contain many harmful substances. These may include endocrine disruptors, which disturb hormonal balance and sperm health. Research on these products is still very new. Therefore at the moment, no one can say for sure what effect vaping has on male fertility.
How do nicotine patches affect male fertility?
Nicotine patches are a good way to ease nicotine cravings and help you quit smoking. You still get small amounts of nicotine, without the harmful toxins and chemicals you get from smoking tobacco. On the whole, nicotine replacement therapies are generally safer than cigarettes. They also prevent your partner from being exposed to secondhand smoke.
However, there’s some evidence from animal studies that nicotine-only therapies may still be damaging to male fertility. So, it’s best to consider nicotine patches as a short-term step to quitting or reducing tobacco use, instead of a long-term solution.
Should I quit smoking if trying to conceive?
Unequivocally yes. Smoking has a negative impact on sperm concentration, motility, morphology, and DNA fragmentation, as well as the health of your partner and potentially even your future child.
The good news: Studies show that sperm health can recover after quitting smoking. It takes around three months for sperm to reach full maturity (74 days, to be exact). So you should expect an improvement in any smoking-related fertility concerns after about three months.
In a follow-up study of men who quit smoking, sperm motility and morphology began to return to normal within an average of six months. And research shows that former smokers who quit more than six months ago might have similar semen parameters to non-smokers.
Quitting smoking is not easy, especially if you are under added stress or worried about trying to conceive with your partner. If you do want to quit smoking, here are a few tips:
- Write down why you want to quit smoking, and keep it accessible to remind you. “Creating a healthy family” is a great reason!
- Pick a quit date and prepare beforehand. Throw out your cigarettes, cigars, or other tobacco products.
- Tell your friends, family, and colleagues you are quitting smoking. Ask for their support and encouragement.
- Speak to your healthcare provider about using nicotine replacement therapy (nicotine patches) or prescription medication.
- Find support that works for you. The CDC suggests the following resources:
- Get free confidential coaching through a telephone quitline (1-800-QUIT-NOW)
- Use a mobile app like quitSTART
- Sign up for free texting programs like SmokefreeTXT
- Find a local quit smoking counselor or support group.
- Learn your triggers and how to avoid them. For example, if you used to smoke on a coffee break with specific coworkers, mix it up and visit a local park on your break instead. If you tend to smoke when you drink, avoid drinking, or recruit a friend to remind you of your goal.
- Keep cravings at bay by keeping busy, exercising, or taking up a new hobby.
It is possible to quit. Since 2002, there have been more people who have quit smoking than current smokers. The key is to get support. You don’t have to try and quit alone.
Sperm testing, from the comfort of home
If you’re a smoker and want to know how your fertility is being affected — or you recently quit and want to know if your sperm health has recovered — test your sperm. A semen analysis with Legacy is an easy at-home way to understand where your fertility stands now.